Combination kiln and heater.



' C. D. ALLAN.

COMBINATION KILN AND HEATER.

APPLICATION FILED DEC. 26, 1913.

1,099,632, r Patented June 9,1914.

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"UNITED STATES PATENT OFFICE.

CHARLES I). ALLAN, OF CHICAGO, ILLINOIS.

COMBINATION KILN AND HEATER.

To all whom it may concern.-

Be it known that I, CHARLES I). ALLAN, a citizen of the United States,and a resident of Chicago, in the county of Cook and State of Illinois,have invented a certain new and useful Improvement in Combination Kilnsand Heaters, of which the following is a specification.

My invention relates to kilns of the type now in common use for burningor firing certain clay products.

In the manufacture of clay products, such as tiling of the kind largelyused in lobbies, bath-rooms, vestibules, etc., the product is firstdried in kilns of the tunnel type, or specially construct-ed dryingrooms, these kilns or rooms being heated by steam in coils or radiators.When the moisture has been driven off, the tile vor other product ispacked in fire clay boxes known as saggars and these saggars are thenplaced in the kiln where the product contained therein is subjected tothe direct heat produced by the furnaces which surround the base of thekiln, and which operates to vitrify the contents of said saggars intothe finished product.

When the kiln is started, it is cold and must be heated gradually and,during this heating up period, the hot gases produced by combustion inthe furnaces at the base of the kiln, are permitted to pass directlyupward through the kiln and to escape through openings in the innercrown or roof thereof. After the kiln is thoroughly heated up, theopenings in the inner crown of the kiln are closed by means of dampersprovided for the purpose, which forces the hot gases downward and outthrough openings in the floor of the kiln, whence they pass under thefloor of the kiln to openings formed in the base of the central stack ofthe kiln through which they are discharged into the space between theinner and the outer crowns, and from thence into the atmosphere. As atpresent constructed, said stack terminates flush with the top of theinner crown of the kiln, and is controlled by means of a suitable damperprovided for the purpose.

A kiln burning usually requires about 7 2 hours, during which time thefuel equivalent of from 400,000 to 500,000 cubic feet of natural gas isconsumed, having a heat value of about 900 B. T. U. per cubic foot, therate of combustion increasing from a small amount, during the time thekiln, with Specification of Letters Patent.

Application filed December 26, 1913.

Patented June 9, 1914-.

Serial No. 808,784.

its contents, is being heated up, to a gas consumption of 7000 cubicfeet per hour during the last 2 1-. hours, having a heat value of0,300,000 13. T. U. per hour, or approximately 200 boiler horse power.After the kiln. is heated to a desired temperature,

the process being only partially, if at all, chemically endothermic incharacter, it follows that a great percentage of the heat, probably 50%or more, passes out through the top of the kiln and is wasted, nosatisfactory method of using this heat having yet been found of which Ihave any knowledge.

The object of the present invention is to provide means in combinationwith a kiln of the general type described, whereby this waste heat canbe utilized for the initial drying of the product or for other purposes,preferably through the medium of a system of hot water heating underforced circulation.

To effect this object a device of my invention comprises the variousfeatures, combinations of features and detail of constructionhereinafter described and claimed.

In the accompanying drawings in which my invention is fully illustrated,Figure 1 is a vertical, central, sectional view of a combined kiln andheater of my invention. Fig. 2 is a sectional plan view thereof on theline 22 of Fig. 1; and Fig. 3 is a sectional plan view thereof on theline 3-4-3 of Fig. 1.

As shown in the drawings, my improved water heater is shown incombination with a kiln of the familiar type comprising a chamber Aformed by side walls A an inner crown or roof A and a floor A upperchamber B, the side walls B of which form an extension of he side wallsA of the chamber A, and which converge upwardly. The top of the chamber13 is open to permit the products of combustion. which enter saidchamber B from the chamber A to escape freely into the atmosphere. Boththe chainbers A and B are preferably circular in cross section. Heat isadapted. to be supplied to the kiln by furnaces C arranged around thebase of the kiln and which communicate directly with the lower chamber Aof the kiln through fines or openings 0 at the inner ends thereof.

Formed in the inner crown or roof in of the chamber A are holes oropenings at, which are adapted to be closed by removable dampers orcovers a holes a being formed in the walls B to provide access to saiddampers, and formed in the floor of said chamber A are holes or openingsa which connect said chamber A with a chamber a located below the floorof the chamber A and which communicates with a vertical stack Aconcentric with chamber A by means of openings (1, formed in the base ofsaid stack A When the holes or openings (4 in the inner crown A of thechamber A are open, the products of combustion will pass directly fromsaid chamber A through said holes or openings into the chamber B, whencethey will escape through the open upper end of said chamber B into theatmosphere. When the holes or openings at in the inner crown A of thechamber A are closed, the products of combustion will pass downwardlythrough the holes or openings (4 in the floor of the chamber A into thechamber a thence through the openings a into the stack A, upwardlythrough said stack into the chamber B and out through the open end ofsaid chamber B as before. As heretofore constructed the Vertical centralstack A has terminated substantially flush with the top of the innercrown A and the chamber B has been entirely vacant.

As regarding its usual features, and excepting as hereinafterparticularly described, the kiln shown in the drawings conforms to theforegoing type and will be readily understood by persons familiar withthe art without a further detailed description thereof.

In accordance with my invention, the stack A is extended a considerabledistance above the inner crown A of the chamber A, as shown at 1, andcommunication between the interior of the stack A and the interior ofthe chamber B is controlled by a damper 2 carried at the inner end of alever 3 pivoted at 4 in an opening 5 formed in the wall B of the chamber13.

Supported on a suitable foundation within the chamber B and surroundingthe stack extension 1 in said chamber is a heater, designated as a wholeD, and which consists of inner and outer shells 6 and 7 and tubes 8arranged in the space between said shells 6 and 7 the ends of whichtubes are secured in heads or tube sheets 9 and 10 which close the spacebetween said shells 6 and 7 in which the tubes 8 are located.

Formed at the lower end of the heater D below the tube sheet 10 is achamber 11 which is in open communication with the lower ends of thetubes 8 and which chamber 11 communicates with the interior of the stackA and its extension 1 by means of openings 12 formed in said stack A orits extension 1. Communication between the interior of the stack A andthe lower ends of the tubes 8, through the openings 12 and the chamber11 is controlled by an annular louver damper 13 which divides said chamber 11 into upper and lower compartments, the upper compartmentcommunicating directly with the tubes 8 and the lower compartment withthe stack openings 12. As shown, see particularly Fig. 3, the damperopenings are shown in open position in full lines and in closed positionin dotted lines. As shown, the chamber 11 is formed partly by the lowerends of the inner and outer shells 6 and 7, which extend somewhat belowthe lower tube sheet 10, and partly by the setting or foundation 1% forsaid heater, on which the lower end of the outer shell 7 of the heaterrests. Communicating with said heater D adjacent to its lower and upperends, respectively, are an admission pipe 15 and a discharge pipe 16,which connect said heater to a hot water heating system, preferably ofthe forced circulation type.

In practice the method of operating a heater of my invention incombination with a kiln of the kind described is as follows: After thespace A of the kiln is packed full of saggars containing the clayproduct to be burnt or fired, the furnaces C are lighted. lVhen the kilnis first started and while it is being heated up, the hot waste gases ofcombustion from the furnaces C pass up through the chamber A and outthrough the openings a in the inner crown A of said chamber A into thechamber B, and from the upper end of said chamber B into the outsideatmosphere. After the kiln and its contents are thoroughly heated, theopenings a in the inner crown A and the damper 2 at the upper end of thestac I 4 are closed, and the annular louver damper 13 is open which willcause the hot waste gases of combustion to pass downwardly through theopenings a in the floor of the chamber A, through the chamber a beneathsaid floor, through the openings (4 into the stack A through theopenings 12, through the chamber 11 upward through the tubes 8, throughthe upper end of the chamber B, and thence into the outside atmosphere.

It is obvious that if the circulating water of a system of hot waterheating passes into the space in the heater D surrounding the tubes 8,through the inlet pipe 15 and out through the outlet pipe 16, at thesame time that the hot waste gases of combustion are passing through thesaid tubes 8, that the said circulating water will be heated to a highdegree. If the said circulating water should be heated to a temperatureover and above that which is desired, then the damper 2 may be partlyopened and the annular louver damper l8 partly closed to an extent thatany part of the hot waste gases of combustion may be utilized forheating the circulating water and the balance may pass out to theatmosphere, thus securing regulation of the amount of heat imparted tothe circulating water through manipulation of the dampers 2 and 13. Toprevent injury to the heater D from over heating when not in use, theinner shell 6 of said heater is preferably made somewhat larger than theextension 1 of the stack A and is spaced therefrom on all sides as shownat 17.

I claim 1. In combination with a kiln of the type described, anextension of the stack of the kiln above the inner crown thereof, awater heater comprising inner and outer shells which surround said stackextension, tubes in the space between said shells, tube sheets whichinclose a space between said shells in which tube sheets the tubes aresecured, said kiln and heater being provided with communication betweenthe interior of the stack and the heater tubes, means for regulating thearea of free opening of said communication, and means for regulating thefree area of opening of stack above the line of communication of itsinterior with the tubes, substantially as described.

2. In combination with a kiln of the type described, an extension of thestack of the kiln above the inner crown thereof, a water heatercomprising inner and outer shells which surround said stack extension,tubes in the space between said shells, tube sheets which inclose aspace between said shells in which tube sheets the tubes are secured, achamber at one end of said heater comprising separate communicatingcompartments,

one of which communicates with the heater tubes and the other with theinterior of the stack, means for regulating the area of free openingbetween the two compartments of said chamber, and means for regulatingthe area of free opening of the stack above the point of itscommunication with the aforesaid chamber, substantially as described.

3. In combination with a kiln of the type described, an extension of thestack of the kiln above the inner crown thereof, a water heatercomprising inner and outer shells which surround said stack extension,the inner-shell being larger than and being spaced from said stackextension, tubes in the space between said shells, tube sheets whichinclose a space between said shells in which tube sheets the tubes aresecured, said kiln and heater being provided with communication betweenthe interior of the stack and the heater tubes, means for regulating thearea of free opening of said communication, and means for regulating thearea of free opening of stack above the line of communication of itsinterior with the tubes, substantially as described.

In testimony that I claim the foregoing as my invention, I aflix mysignature in the presence of two subscribing witnesses this 23rd day ofDecember, 1913.

CHARLES D. ALLAN.

itnesses A. H. GUNeeoLL, ALEX. D. KING, J r.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

